arch/arm/mach-msm/gpiomux.h

   1 /* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  15  * 02110-1301, USA.
  16  */
  17 #ifndef __ARCH_ARM_MACH_MSM_GPIOMUX_H
  18 #define __ARCH_ARM_MACH_MSM_GPIOMUX_H
  19
  20 #include <linux/bitops.h>
  21 #include <linux/errno.h>
  22 #include <mach/msm_gpiomux.h>
  23 #include "gpiomux-v1.h"
  24
  25 /**
  26  * struct msm_gpiomux_config: gpiomux settings for one gpio line.
  27  *
  28  * A complete gpiomux config is the bitwise-or of a drive-strength,
  29  * function, and pull.  For functions other than GPIO, the OE
  30  * is hard-wired according to the function.  For GPIO mode,
  31  * OE is controlled by gpiolib.
  32  *
  33  * Available settings differ by target; see the gpiomux header
  34  * specific to your target arch for available configurations.
  35  *
  36  * @active: The configuration to be installed when the line is
  37  * active, or its reference count is > 0.
  38  * @suspended: The configuration to be installed when the line
  39  * is suspended, or its reference count is 0.
  40  * @ref: The reference count of the line.  For internal use of
  41  * the gpiomux framework only.
  42  */
  43 struct msm_gpiomux_config {
  44         gpiomux_config_t active;
  45         gpiomux_config_t suspended;
  46         unsigned         ref;
  47 };
  48
  49 /**
  50  * @GPIOMUX_VALID:      If set, the config field contains 'good data'.
  51  *                      The absence of this bit will prevent the gpiomux
  52  *                      system from applying the configuration under all
  53  *                      circumstances.
  54  */
  55 enum {
  56         GPIOMUX_VALID    = BIT(sizeof(gpiomux_config_t) * BITS_PER_BYTE - 1),
  57         GPIOMUX_CTL_MASK = GPIOMUX_VALID,
  58 };
  59
  60 #ifdef CONFIG_MSM_GPIOMUX
  61
  62 /* Each architecture must provide its own instance of this table.
  63  * To avoid having gpiomux manage any given gpio, one or both of
  64  * the entries can avoid setting GPIOMUX_VALID - the absence
  65  * of that flag will prevent the configuration from being applied
  66  * during state transitions.
  67  */
  68 extern struct msm_gpiomux_config msm_gpiomux_configs[GPIOMUX_NGPIOS];
  69
  70 /* Install a new configuration to the gpio line.  To avoid overwriting
  71  * a configuration, leave the VALID bit out.
  72  */
  73 int msm_gpiomux_write(unsigned gpio,
  74                       gpiomux_config_t active,
  75                       gpiomux_config_t suspended);
  76
  77 /* Architecture-internal function for use by the framework only.
  78  * This function can assume the following:
  79  * - the gpio value has passed a bounds-check
  80  * - the gpiomux spinlock has been obtained
  81  *
  82  * This function is not for public consumption.  External users
  83  * should use msm_gpiomux_write.
  84  */
  85 void __msm_gpiomux_write(unsigned gpio, gpiomux_config_t val);
  86 #else
  87 static inline int msm_gpiomux_write(unsigned gpio,
  88                                     gpiomux_config_t active,
  89                                     gpiomux_config_t suspended)
  90 {
  91         return -ENOSYS;
  92 }
  93 #endif
  94 #endif